What's the saddest song you ever heard

For me it's "Me and My Brother" by 5ive.​

Which addition property is being illustrated below? (type commutative or associative) (6 + 7) + 1 = 6 + (7 + 1)

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.